The present invention generally relates to spill containment apparatus and methods for preventing undesirable discharge of chemical materials onto the ground. More particularly, it relates to new and improved spill containment devices and methods for use primarily by the railroads including one or more lidded catch pans positionable generally around and under a transportation container for collecting and containing spilled or dripping chemical materials.
With increased public and governmental awareness of groundwater contamination caused by various industries including the petro-chemical industry, companies are reviewing their chemical transfer operations to minimize their legal and environmental exposure. Traditionally, railroad tank car unloading has been relatively unregulated and most railroad track sidings reflect that level of unconcern with "minor" discharges of whatever was being loaded or unloaded. Often the commodity being shipped was inexpensive per gallon or perceived to be of little economic impact to the company, and therefore, any spills were either hosed down or just left for the next rain to clear away. With the advent of stiff fines and high soil remediation costs, the idea of spill containment pans under the tank car becomes the prophetic ounce of prevention that eliminates a pound of cure.
As petro-chemical technology develops more exotic compounds, the cost per gallon has increased. The increase in road trucking costs and the adoption of hazardous materials shipping regulations and restricted truck routes have made many shippers reconsider using railroad tank cars and drums in railroad box cars. Since spills most often occur during the loading and unloading operation, well-designed, clean spill containment pans can recapture these valuable commodities. Often, if these pans do not contain dirt and rainwater, the material accidentally discharged and recaptured in the containment pan can be collected and economically reused.
Currently, many chemical companies use spill pans that actually are only diversion aprons that require construction of some type of collection sump. These sumps are subject to crack failure or filling with dirt and water. Since collection pans are subject to rainwater, snow and blowing dirt and debris, their effectiveness as spill containment is questionable. Environmental regulations state that any rainwater collected in these chemical spill containment pans is considered contaminated and must be handled with the same concern and "cost" as hazardous waste.
Prior art efforts to provide spill containment for leaking, dripping and spilled materials particularly oily materials have included providing a flexible plastic drop cloth or sheet which forms a barrier to prevent contact of the chemical material with the ground. The plastic sheet is either suspended or mounted to the underside of a transport vehicle, as in U.S. Pat. No. 4,936,418 for example, or it is provided with inflatable or raised edge structures to funnel fluids to a sump or collecting area as is described in U.S. Pat. No. 5,099,872. The barrier sheet type containment arrangements generally do not include any means for preventing unwanted ingress of rain, sleet, snow, dirt, dust and other environmental contaminants.
Catch pans with convertible lidded structures are known in the art as taught in U.S. Pat. Nos. 5,052,422 and 4,651,887. The latter patent is designed for use between the rails of a railroad siding. The spill pan described in the '887 patent is generally effective for containing spills and drips falling directly downward between the rails. The pan has a generally transverse orientation between the rails which requires direct overhead placement of the rail car and its openings in order to be in proper position for use. Moreover, the containment apparatus defined in the '887 patent does not provide any means for catching and collecting outboard spills occurring alongside the rails instead of between them.
In order to overcome the deficiencies of the prior art devices and methods, it is an object of the present invention to provide a new and improved spill containment apparatus for use with railroad equipment extending parallel to a railroad siding so that careful placement of the rail car over a precise location is not required.
It is another object of the present invention to provide a spill containment apparatus for beside the rails use, as well as for between the rails use to provide more effective environmental spill protection for loading and unloading operations for the railroads.
It is a further object of the present invention to provide a new and improved spill containment apparatus including a movable lid structure to prevent undesired ingress of environmental contaminants when not in use and which opens outwardly to effectively enlarge the surface area of ground protected from spill contamination.